The present invention relates generally to gas turbines, and more particularly to a hybrid blisk for a gas turbine.
Gas turbines include, among other variations, gas turbine power generation equipment and gas turbine aircraft engines. A gas turbine includes a core engine having a high pressure compressor, a combustor in which a mixture of fuel and compressed air is burned to generate a propulsive gas flow, and a high pressure turbine which is rotated by the propulsive gas flow and which is connected by shaft to drive the high pressure compressor. A typical gas turbine aircraft engine adds a low pressure turbine which is connected by another shaft to drive a fan rotor. The fan rotor is one of the heaviest components of this type of engine.
The fan rotor carries a plurality of airfoil-shaped blades, usually installed in an array of dovetail slots. Conventional gas turbine blade designs typically are made entirely of metal, or of a composite material such as carbon-epoxy composite. All-metal blades, including costly wide-chord hollow blades, are relatively heavier in weight which results in lower fuel performance and which requires sturdier blade attachments, while the relatively lighter all-composite blades are more susceptible to damage from bird strikes. Known hybrid blades include composite blades whose leading edge is protected by metal for erosion and bird impact reasons, and metallic blades with nonmetallic inserts. While these hybrid blades reduce the weight of the fan rotor, they still require a separate mechanical attachment to the rotor.
Accordingly, there is a need for a fan rotor which is both light-weight and impact resistant.